I bought this Supernova power supply back in 2015 and didn't install it for several years (after ordering, my UPS tripping on dirty power turned out to be actual line workers a block over and not my old PSU). Eventually I installed the EVGA PSU and it seemed to run my 2nd gen/sandy bridge system fine, except every so often I'd find the computer wouldn't start up after it went to sleep/powered down. It basically ignored the button press to power up, although coming back an hour or two later it would run (maybe not the first attempt, but eventually). I attributed it to my older sandy bridge-era hardware and used that as part of the reason to replace my computer.
Enter my newer system, where I have an evga Z370 ftw board and migrated the evga gs 850 PSU over to this 9th gen system. I assembled it over the weekend and I've observed the exact same behavior with the power supply refusing to respond to the power button on the case and also not respond to the power button on the motherboard. I've unplugged all the modular cables and then used the 24 pin connector + PSU tester and observed the PSU power up, but then still had the PSU refuse to power up when I reconnected all the modular cables again. The problem has been intermittent, but I kind of think it's happening more frequently lately (and it's no fun when your new build refuses to start).
I've done a quick search for others with the same issue with GS PSUs and came up with similar stories.
the urls are stripped but they're posts - I-think-my-SuperNova-850-GS-is-failing-m2601784, Supernova-850-GS-PSU-problems-2nd-unit-m2488599, Possible-issue-with-850-GS-and-booting-m2396853
As part of my diagnosing the problem, I completely disconnected the case's power switch at the motherboard header and figured I'd just rely on the motherboard's power button. The computer didn't post and I resumed writing this post on my old computer, but several minutes later the computer with the evga PSU has just fired up on its own, without even pressing the power button on the motherboard.
I think I need to open an RMA for this PSU, but is there some more advanced logic going on if you use a motherboard's power button vs just a short at the PSU's 24 pin cable (as the PSU tester does)? I'm kind of at a loss as to what I can diagnose here, but the same intermittent behavior from the same PSU in two different computers sure does appear to indicate the PSU.
post edited by chefjoe - 2019/07/03 14:04:37